Method of forming u-shaped buckets or pockets in the rims of gas or steam turbines.



.PATENTED JULY 19, 1904. M. KAUFHOLD & J. HOPPMA'NN. METHOD OF FORMINGU-SHAPED BUGKETS 0R POGKETS IN THE RIMS i OF GAS 0R STEAM TURB'INES.

N0 MODEL.

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Patented July 19, 1904.

UNITED STATES PATENT OFFICE.

MAX KAUFHOLD AND J USTUS HOFFMANN, OF ESSEN, GERMANY, ASSIGNORS TOMASCHINENBAU-ACTIEN-GESELLSCHAFT UNION, OF ESSEN, PRUSSIA, GERMANY.

METHOD OF FORMING U -SHAPED BUCKETS 0R POCKETS IN THE RIMS 0F GAS ORSTEAM TURBINES.

SPECIFICATION forming part of Letters Patent No. 765,284, dated July 19,1904. Application filed February 5, 1904. Serial No. 192,186. (Nomodel.)

To alt w/mm it may concern.-

Be it known that we, MAX KAUFHOLD, a subject of the King of Prussia,residing at No. 7 Elisabethstrasse, Essen, in the Kingdom of Prussia,German Empire, and Jus'rus HOFF- MANN, also a subject of the King ofPrussia, residing at No. 118 Schlenhofstrasse, in the same town, haveinvented an Improved Method of Forming Pockets in Turbines, of which thefollowing is a specification.

This invention relates to that description of turbines worked by steamand gaseous pressure in which the rims of the turbine-wheels 'andtheguide-rings are formed with U-shaped buckets or pockets," in which theentering steam or gas is caused to turn back through an angle of onehundred and eighty degrees.

In order to insure a change in direction of the motive fluid of onehundred and eighty degrees, it is necessary that the curved lowerportion of the recess should correspond to a complete half-circle, andthis is only rendered possible when formed with a disk-cutter having itsshaft projecting at an angle with the plane thereof by providing in thatportion of the metal overhanging thev pockets a slot to receive theshaft of the cutter, and thus permit the cutter to enter more deeplybeneath the surface of the wheel.

According to a known method of forming these buckets or pockets they areproduced by a stepped rotary cutter, of which the part of largerdiameter serves to cut out the bucket, while the part of smallerdiameter cuts a slot in the part of the metal overhanging the bucket.

The present invention relates to a method of forming the said'buckets orpockets by means of a simple rotary cutter instead of by means of acompound or stepped cutter, as heretofore, this being rendered possibleby first forming the slots in the part of the metal overhanging thebuckets or pockets, by means of which space is afforded for the shaft ofthe rotary cutter for cutting the buckets, so that this can effect thecomplete cutting out thereof. The said slots can be produced either bycutting a peripheral groove all round the turbine-wheel or by merelyboring or cutting holes in the periphery at the required points.

" Figures 1 and 2 of the accompanying drawduced by first cutting acircular groove 6 of the required shape round the periphery of thewheel, the width of 'the groove being about equal to the diameter of theshaft of the rotary cutter that is to cut the buckets. The U-shapedbuckets a can then be cut in the wheel 0 by means of a simple rotarydisk cutter, the shaft of which enters the notches or slots (Zpreviously formed as the cutter moves inward during the progress of thecutting.

In the arrangement shown in Figs. 3 and 4 there are first formed in theperiphery of the turbine-wheel at those points where the slots d have tobe situated holes 0, produced by boring or cutting, the diameter ofwhich is about equal to the diameter of the shaft of the rotary cutterwhich is to cut the buckets. These are then cut to a depth determined bythe coming in contact of the cutter-shaft with the end of the slotproduced by the previouslybored hole.

As shown in Fig. 3, the-walls of the slots (Z, formed according to thelast-described method, are at right angles to the surfaces of the metalcovering the buckets, while the slots formed by previously cutting thecircular groove 6 have their walls lying obliquely to the surfaces ofthe metal, so as to produce a sharp inner edge f, Fig. 1, whereby asmaller loss by leakage is insured.

Having thus described the nature of this invention and the best means weknow of carrying the same into practical effect, we claim 1. The methodof forming U-shaped pockets in turbine-Wheels, which consists in cuttingaway the periphery of the wheel at points I corresponding to the axes ofthe pockets, and means of a rotary cutter having its shaft cor- 10 thenforming the pockets by means of a roresponding with the groove.

tary cutter having its shaft corresponding 1n witn'esswhereof We havehereuntoset our With the cut-away portions of the wheel. hands inpresence of two Witnesses. 5 2. Themethodot' forming U-shapcd pocketsMAX KAUFHOLD.

in turbine-Wheels, which consists in cutting JUSTUS HOFFMAN N a groovein the periphery of the Wheel at a Witnesses: position corresponding tothe axes of the WILLIAM EssENwEIN, pockets, and then forming the pocketsby PETER LIEBER.

